1. Field of the Invention
This invention relates to an improved intravaginal contraceptive barrier and, more particularly, to a disposable thermoplastic vaginal diaphragm with controlled release of spermicidal agent and method of making the same.
2. Description of the Prior Art
As an intravaginal contraceptive barrier, the diaphragm--usually a soft rubber cup with a reinforced rim that is inserted into the vagina to block access of sperm to the cervix--is an excellent alternative for women who have conditions which do not allow the use of oral contraceptives or IUD or who do not wish to use these methods. Although the diaphragm is usually 100% risk-free and can be a reliable contraceptive for most women, to be effective it must be used properly.
There are generally four (4) types of commercially available diaphragms. The coil-spring diaphragm contains a round, spiral-coiled, metal wire in the rim which is encircled with rubber. This type of diaphragm is particularly suited for women with strong vaginal muscles and a vagina of normal size and contour. The flat-spring diaphragm has a flat, metal band in the rim, and it is firmer than the coil-spring type. The archingspring diaphragm combines features of both coil-spring and flatspring diaphragms. A double metal spring in the rim produces strong pressure against the vaginal walls, and it is used primarily by women with poor vaginal muscle tone. Finally, the Matrisalus diaphragm has a strong, flat steel band in the rim which is curved instead of round to place an added lift against the anterior vaginal wall.
Many factors associated with the use of presently available diaphragms have prevented their wide spread use. While the diaphragm acts as a barrier to most sperm, it is not normally held tightly enough in front of the cervix to prevent entirely the passage of all sperm around the rim. Therefore, the device is used in most instances with a spermicidal cream or jelly. The spermicides are often messy and tend to flow out of the vagina. Replenishing the spermicide can be expensive if the diaphragm is used frequently. The use of conventional diaphragms not only interrupts the normal love-making sequence, but it presents problems with maintenance associated with diaphragm washing, drying, powdering, and inspection.
Numerous contraceptive devices have been developed to eliminate the disadvantages of current reusable diaphragms. Prior art annular devices provide controlled release of surfactant-type spermicides in the vagina, but they do not act as a barrier to sperm deposition on or in the area of the cervix. Devices with compartments that substantially cap or block the cervix and provide controlled release of spermicidal surfactants have been disclosed; however, these devices are not disposable, and they are designed to remain in the vagina and release spermicide during the time between menstrual periods. Because of this length of use, they may develop problems with odor or discomfort, and they are less suited for women who engage in sexual intercourse infrequently.